hydrated CoCl2 is a deep purple color. After being heated for a long time, it turns into its anhydrous form, which is sky blue. Is this a chemical or physical change

You are performing an experiment in a lab to attempt a new method of producing pure elements from compounds. the only problem is that you do not know what element will form. by your previous calculations you know that you will have 6.3 moles of product. when it is complete, you weigh it and determine you have 604.4 grams. what element have you produced?

There are main groups in the modern periodic table of elements

Given the data below for the reaction, 2 a + 2 b + 4 c => d + e + 3 f, the reaction is fill in the [ ] order in a, fill in the [ ] order in b, fill in the [ ] order in c and fill in the [ ] order overall. (use the words "first, second, third, fourth" to fill each blank)experimentinitial conc of a, mol/l initial conc of b, mol/l initial conc of c, mol/l initial rate, mol/l.s1 0.1 0.1 0.2 2 x 10-32 0.2 0.3 0.2 6 x 10-33 0.3 0.1 0.2 2 x 10-34 0.4 0.3 0.4 1.2 x 10-2